Re: Profiling a build

[Sad Clouds <cryintothebluesky%gmail.com@localhost>]

On Tue, 2 Dec 2025 12:36:21 +0000 (UTC)
Benny Siegert <bsiegert%netbsd.org@localhost> wrote:

> But the thing is, I want to measure build performance taking into account 
> disk I/O and all of that. Also, the amount of RAM is tight already, so I 
> cannot afford a ramdisk :/

I would use a different system with enough RAM. I would run first build
on disk, then run second build on tmpfs. Compare two values to see the
disk I/O overhead. Use only a single CPU to keep timings consistent.

Disk I/O has nothing to do with build tool performance. It's just
another variable that has an impact on the amount of time it takes to
complete build jobs. However with different storage subsystems that
will change drastically. You can measure disk performance directly with
tools like dd.

Some time ago I measured how NetBSD build.sh scales on tmpfs with
multiple CPU cores. I think it has a lot of serial sections which
inhibit its scalability on large systems.